JP2016053703A - Toner supply device and image forming apparatus including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner supply device that has a backflow prevention wall provided inside a toner storage chamber and can supply, to a toner conveyance path, a toner inside a space for storing a toner supplied from a toner supply source to the toner storage chamber.SOLUTION: There is provided a toner supply device including a first toner storage space 81, a second toner storage space 82, a toner conveyance pipe 43 including a toner conveyance screw 70 therein, an agitator 80 that rotates to agitate the toner inside the first toner storage space 81 and convey the toner to the second toner storage space 82, and a backflow prevention wall 83 that prevents backflow of the toner, where the agitator 80 has bent parts bent in the direction on the upstream side in the direction of rotation provided at least at one or more positions, and when the tip of the agitator 80 passes through the uppermost end of the backflow prevention wall 83, the position of the bent part closest to the tip of the agitator 80 is located above the uppermost end of the backflow prevention wall 83 in the vertical direction.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a toner replenishing device that feeds toner in a toner accommodating portion to a developer accommodating portion by a toner replenishing conveying member, and an image forming apparatus including the toner replenishing device.

  Conventionally, as a toner replenishing device for replenishing toner to a developing device that performs development of an image forming apparatus, a toner bottle containing toner is attached to the toner replenishing device, and toner is supplied from the toner bottle to the developing device using this toner replenishing device. What is replenished is known. This toner replenishing device has a toner accommodating portion that temporarily accommodates toner supplied from a toner bottle, and the toner in the toner accommodating portion passes through a toner conveying path having a toner replenishing conveying member therein to the developing device. Sent.

  Patent Document 1 describes such a toner replenishing device provided with a stirring member that rotates in a toner container and stirs toner. Thus, the toner can be prevented from aggregating in the toner accommodating portion.

  FIG. 13 is a diagram illustrating a schematic configuration of a toner supply device under development. As shown in FIG. 13, the hopper 148 includes two spaces, a first toner storage space 181 and a second toner storage space 182. The first toner storage space 181 includes a stirring member 180 that rotates about the rotating shaft 173 and stirs the toner. The stirring member 180 is formed of an elastic material. The second toner storage space 182 is adjacent to the first toner storage space 181 and is connected to the inlet 184 of the toner transport path 143.

  A backflow prevention wall 183 is provided between the first toner storage space 181 and the second toner storage space 182 so that the toner supplied from the first toner storage space 181 to the second toner storage space 182 by the stirring member 180 does not flow backward. Is provided. When the tip of the stirring member 180 is at the same height in the vertical direction as the uppermost end (point T in the figure) of the backflow prevention wall, the normal vector (arrow C in the figure) of the upper surface of the stirring member is the second toner. It is not suitable for the accommodation space 182.

  The toner in the toner bottle body 133 falls from the discharge port 160 of the resin case 134 into the first toner storage space 181. The toner bottle main body 133 is rotated by a drive motor. At the same time as the bottle body 133 rotates, the stirring member 180 and the toner replenishment transport member in the toner transport path 143 rotate simultaneously.

The toner conveying operation from the first toner storage space 181 to the second toner storage space 182 by the stirring member 180 will be described with reference to FIG.
FIG. 14 is an enlarged view of a portion surrounded by a dotted line W in FIG. FIG. 14A shows a state where the tip of the stirring member 180 is passing through the backflow prevention wall 183. The toner in the first toner storage space 181 is pumped up on the upper surface of the rotating stirring member 180. When the tip of the stirring member 180 is pressed against the backflow prevention wall 183, the stirring member 180 is bent. At this time, the tip of the stirring member 180 is directed upstream with respect to the axial rotation direction (arrow V in the figure).

  FIG. 14B shows a state at the moment when the tip of the stirring member 180 passes through the uppermost end (point T in the figure) of the backflow prevention wall 183. As described above, the normal vector (arrow C in the drawing) on the upper surface of the stirring member 180 does not face the second toner storage space 182. For this reason, when the bending of the stirring member 180 is released, the toner at the tip of the stirring member 180 is splashed up in the directions indicated by arrows F, G, and H in the drawing. As shown by an arrow F in the figure, the toner splashed in the direction toward the second toner storage space 182 is guided from the inlet 184 to the toner conveyance path 143. However, the toner splashed in the direction other than the direction toward the second toner accommodating space 182 as indicated by arrows G and H in the drawing is not sent to the toner conveyance path 143 and remains in the hopper 148. As shown by an arrow G in the figure, the toner splashed right above the backflow prevention wall 183 is deposited on the uppermost end of the backflow prevention wall 183. Since the tip of the stirring member 180 does not reach the position of the uppermost end of the backflow prevention wall 183, a part of the toner accumulated here solidifies and stays there.

  FIG. 14C shows a state after the tip of the stirring member 180 has passed the uppermost end (point T in the drawing) of the backflow prevention wall 183. After the tip of the agitating member 180 passes the uppermost end (point T in the figure) of the backflow prevention wall 183, a part of the toner other than the tip of the agitating member 180 exerts a centrifugal force in the direction of arrow D in the figure. In response, the toner is blown into the second toner storage space 182. However, since the normal vector (arrow C in the figure) on the upper surface of the stirring member 180 is not directed toward the second toner containing space 182, the toner placed on the portion other than the tip of the stirring member 180 is stirred. A frictional force is applied from the upper surface of the member 180 in the direction of arrow I in the figure. For this reason, most of the toner placed on the portion other than the tip of the stirring member 180 moves in the direction of arrow E in the drawing together with the stirring member 180. Therefore, most of the toner on the portion other than the tip of the stirring member 180 remains in the hopper 148 without being sent to the toner conveyance path 143.

  As described above, the toner replenishing device having the configuration shown in FIG. 13 has a problem that the toner in the first toner storage space cannot be efficiently conveyed to the toner conveyance path. Further, this problem is not limited to the toner replenishing device shown in FIG. 13, and the normal vector on the upper surface of the stirring member is equal to the first vector when the tip of the stirring member is at the same height in the vertical direction as the uppermost end of the backflow prevention wall. Any toner replenishing device having a configuration not suitable for the two-toner accommodating space may occur. To counter this problem, it is conceivable to reduce the height of the backflow prevention wall. However, since this reduces the effect of preventing the backflow of toner, the toner in the first toner storage space is also efficiently transported to the toner. Cannot be transported to the route.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a space in a space for accommodating toner supplied from a toner replenishment source to a toner storage chamber when a backflow prevention wall is provided in the toner storage chamber. It is an object of the present invention to provide a toner replenishing device that can send toner to a toner conveyance path without delay.

  A first toner storage space that is a space for storing toner supplied from a toner replenishment source, a second toner storage space adjacent to the first toner storage space, and the second toner storage space, and developing toner. A toner transport path having a transport member for transporting into the apparatus, and the toner in the first toner storage space are agitated by rotating in the first toner storage space and the first toner storage space An agitation member that conveys the toner in the second toner storage space, and is positioned between the first toner storage space and the second toner storage space, and from the first toner storage space to the second toner storage space In the toner replenishing device having a backflow prevention wall for preventing backflow of the toner conveyed to the space, the stirrer is bent to bend the stirrer in the upstream direction with respect to the rotation direction. At least one portion, and when the tip of the stirring member passes the uppermost end of the backflow prevention wall, the position of the bent portion closest to the tip of the stirring member among the bent portions is the backflow prevention. It was made to be above the top end of the wall in the vertical direction.

  When the backflow prevention wall is provided in the toner storage chamber, the toner in the space for storing the toner supplied from the toner supply source to the toner storage chamber can be sent to the toner conveyance path without delay.

1 is a schematic configuration diagram of a printer according to an embodiment. FIG. 3 is an enlarged view of the vicinity of a process cartridge of the printer. FIG. 3 is a perspective view of a toner bottle of the printer. FIG. 3 is a perspective view of a toner bottle and a toner supply device of the printer. The front view of FIG. The bottom view of FIG. An enlarged view of a region surrounded by a dotted line R in FIG. FIG. 3 is a perspective view of a toner conveying screw in the toner supply device. The perspective view etc. which show schematic structure of the hopper of the toner supply apparatus. Explanatory drawing of the conveyance of the toner by the agitator in the hopper. FIG. 6 is a schematic configuration diagram illustrating a modification of an agitator in the toner supply device. FIG. 10 is a schematic configuration diagram illustrating another modification of the agitator in the toner supply device. FIG. 6 is a schematic configuration diagram illustrating an example of a conventional toner supply device. FIG. 6 is an explanatory diagram of a toner conveying operation by a stirring member of the toner supply device. Explanatory drawing about the further another modification of the agitator in the toner replenishment apparatus in the printer which concerns on embodiment. Explanatory drawing about the further another modification of the agitator in the toner supply apparatus. Explanatory drawing about the further another modification of the agitator in the toner supply apparatus. Explanatory drawing about the further another modification of the agitator in the toner supply apparatus.

Hereinafter, an electrophotographic printer (hereinafter simply referred to as “printer 100”) will be described as an embodiment of an image forming apparatus to which the present invention is applied.
First, the basic configuration of the printer 100 will be described. FIG. 1 is a schematic configuration diagram of the printer 100. In the figure, the printer 100 includes four process cartridges 6Y, 6M, 6C, and 6K for generating toner images of yellow, magenta, cyan, and black (hereinafter referred to as Y, M, C, and K). ing. These use Y, M, C, and K toners of different colors as the image forming material, but the other configurations are the same and are replaced when the lifetime is reached. Taking a process cartridge 6M for generating an M toner image as an example, as shown in FIG. 2, a drum-shaped photosensitive member 1M, a drum cleaning device 2M, a charge eliminating device, a charging device 4M, a developing device 5M, and the like are provided. . The process cartridge 6M can be attached to and detached from the main body of the printer 100 so that consumable parts can be replaced at a time.

  The charging device 4M uniformly charges the surface of the photoreceptor 1M that rotates clockwise in the drawing by the driving means. The surface of the uniformly charged photoreceptor 1M is exposed and scanned by the laser beam L and carries an electrostatic latent image for M. The M electrostatic latent image is developed into an M toner image by the developing device 5M using M toner. Then, intermediate transfer is performed on the intermediate transfer belt 8. The drum cleaning device 2M removes the toner remaining on the surface of the photoreceptor 1M after the intermediate transfer process.

  The static eliminator neutralizes residual charges on the photoreceptor 1M after cleaning. By this charge removal, the surface of the photoreceptor 1M is initialized and prepared for the next image formation. In the other process cartridges 6Y, 6C, and 6K, Y, C, and K toner images are similarly formed on the photoreceptors 1Y, 1C, and 1K, and are intermediately transferred onto the intermediate transfer belt 8.

  In FIG. 1 described above, an exposure device 7 is disposed below the process cartridges 6Y, 6M, 6C, and 6K in the drawing. The exposure device 7 serving as a latent image forming unit irradiates the respective photosensitive members in the process cartridges 6Y, 6M, 6C, and 6K with a laser beam L emitted based on the image information. By this exposure, electrostatic latent images for Y, M, C, and K are formed on the photoreceptors 1Y, 1M, 1C, and 1K. The exposure device 7 irradiates the photoconductor with a laser beam (L) emitted from a light source through a plurality of optical lenses and mirrors while scanning with a polygon mirror rotated by a motor.

  On the lower side of the exposure apparatus 7 in the figure, paper supply means including a paper storage cassette 26, a paper supply roller 27 incorporated therein, a registration roller pair 28, and the like are disposed. The paper storage cassette 26 stores a plurality of transfer papers P as recording bodies, and a paper feed roller 27 is in contact with the uppermost transfer paper P. When the paper feeding roller 27 is rotated counterclockwise in the figure by the driving means, the uppermost transfer paper P is fed toward the rollers of the registration roller pair 28.

  The registration roller pair 28 rotationally drives both rollers to sandwich the transfer paper P, but temporarily stops rotating immediately after sandwiching. Then, the transfer paper P is sent out toward a secondary transfer nip described later at an appropriate timing. In the sheet feeding unit having such a configuration, a conveying unit is configured by a combination of the sheet feeding roller 27 and the registration roller pair 28 corresponding to the timing roller. This transport means transports the transfer paper P from a paper storage cassette 26 serving as a storage means to a secondary transfer nip described later.

  Above the process cartridges 6Y, 6M, 6C, and 6K, an intermediate transfer unit 15 that moves the intermediate transfer belt 8 that is an intermediate transfer member endlessly while stretching is disposed. The intermediate transfer unit 15 includes, in addition to the intermediate transfer belt 8, four primary transfer bias rollers 9Y, M, C, and K, a cleaning device 10, and the like. A secondary transfer backup roller 12, a cleaning backup roller 13, a tension roller 14 and the like are also provided. The intermediate transfer belt 8 is endlessly moved in the counterclockwise direction in the figure by the rotational drive of at least one of the rollers while being stretched around these three rollers.

  The primary transfer bias rollers 9Y, M, C, and K sandwich the intermediate transfer belt 8 that moves endlessly with the photoreceptors 1Y, M, C, and K to form primary transfer nips. . In these methods, a transfer bias having a polarity opposite to that of toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 8. All of the rollers except the primary transfer bias rollers 9Y, 9M, 9C, and 9K are electrically grounded. The intermediate transfer belt 8 sequentially passes through the primary transfer nips for Y, M, C, and K along with the endless movement thereof, and Y, M, and C on the photoreceptors 1Y, M, C, and K are sequentially transferred. , K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as “four-color toner image”) is formed on the intermediate transfer belt 8.

  The secondary transfer backup roller 12 sandwiches the intermediate transfer belt 8 between the secondary transfer roller 19 and forms a secondary transfer nip. The four-color toner image formed on the intermediate transfer belt 8 is transferred to the transfer paper P at the secondary transfer nip. Untransferred toner that has not been transferred onto the transfer paper P adheres to the intermediate transfer belt 8 after passing through the secondary transfer nip. This is cleaned by the cleaning device 10.

  In the secondary transfer nip, the transfer paper P is sandwiched between the intermediate transfer belt 8 and the secondary transfer roller 19 whose surfaces move in the forward direction, and is conveyed in the direction opposite to the registration roller pair 28 side. The When the transfer paper P sent out from the secondary transfer nip passes between the rollers of the fixing device 20, the four-color toner image transferred to the surface is fixed by heat and pressure. Thereafter, the transfer paper P is discharged out of the apparatus through a pair of paper discharge rollers 29. A stack unit 30 is formed on the upper surface of the main body of the printer 100, and the transfer paper P discharged to the outside by the discharge roller pair 29 is sequentially stacked on the stack unit 30.

  The configuration of the developing device 5M in the process cartridge 6M will be described. The developing device 5M includes a developing sleeve 51M and a doctor 52M. The developing sleeve 51M is a developer carrying member that includes a magnetic field generating means inside and carries a two-component developer containing magnetic particles and toner on the surface thereof. The doctor 52M is a developer regulating member that regulates the layer thickness of the developer carried and conveyed on the developing sleeve 51M. Here, a place where the developing sleeve 51 is accommodated is referred to as a developing sleeve accommodating portion 53.

  A place where the developer is accommodated adjacent to the developing sleeve accommodating portion 53M is a developer accommodating portion 54M, and the developer accommodating portion 54M includes a developer conveying screw 55M for agitating and conveying the developer. Further, the developing device 5M includes a density detection sensor 56M as a toner density sensor that detects the toner density of the developer in the developer container 54M. Further, a toner replenishing port for taking in toner to be replenished based on the detection result of the density detection sensor 56M into the developer accommodating portion 54M is provided.

  Next, the operation of this developing device will be described. The developer is agitated and conveyed by the rotation of the developer conveying screw 55M and circulates in the developer accommodating portion 54. By being agitated and conveyed, the toner in the developer is charged by frictional charging with the carrier. The developer containing charged toner on the side of the developer accommodating portion 54 adjacent to the developing sleeve accommodating portion 53M is supplied to the surface of the developing sleeve 51M having a magnetic pole inside and is carried by magnetic force. The developer layer carried on the developing sleeve 51M is conveyed in the direction of the arrow as the developing sleeve 51M rotates. In the middle, after the thickness of the developer layer is regulated by the doctor 52M, it is transported to the developing area facing the photoreceptor 1M. In the development area, development based on the latent image formed on the photoreceptor 1M is performed. The developer layer that has passed through the developing area and remained on the developing sleeve 51M is conveyed along with the rotation of the developing sleeve 51M, and is separated from the developing sleeve 51M by the repulsive magnetic force due to the magnetic pole arrangement inside the developing sleeve 51M. The unit 54 is accommodated.

  In FIG. 1 described above, a toner bottle base 31 as a toner bottle storage unit is disposed between the intermediate transfer unit 15 and the stack unit 30 located above the intermediate transfer unit 15. The toner bottle base 31 contains toner bottles 32Y, 32M, 32C, 32K containing Y, M, C, and K toners. The toner bottles 32Y, 32M, 32C, and 32K are installed on the toner bottle base 31 so as to be placed from above for each toner color. The Y, M, C, and K toners in the toner bottles 32Y, 32M, 32C, and 32K are appropriately replenished to the developing devices of the process cartridges 6Y, 6M, 6C, and 6K, respectively, by a toner replenishing device that will be described later. These toner bottles 32Y, 32M, 32C, and 32K are detachable from the printer 100 main body independently of the process cartridges 6Y, 6M, 6C, and 6K.

  FIG. 3 is a perspective view of the toner bottle 32M. As shown in FIG. 3, the toner bottle 32M is provided with a resin case 34M at the tip of the bottle body 33M. A bottle rotation gear 37M that rotates integrally with the bottle body 33 is provided on the resin case 34M side of the bottle body 33. When attaching the toner bottle 32M to the main body of the printer 100, when the toner bottle 32M is inserted into the main body of the printer 100, the shutter 36M moves and opens to open the toner discharge port. At the same time, the resin case 34M and the toner bottle base 31 (see FIG. 1) are connected and fixed.

  On the other hand, to remove the toner bottle 32M from the printer 100 main body, the connection with the toner bottle base 31 is released by pulling out the toner bottle 32M from the printer 100 main body, and at the same time, the shutter 36M is closed and the toner discharge port is closed. Then, the toner bottle 32M can be taken out from the main body of the printer 100 as it is.

Next, the toner conveying unit will be described.
Hereinafter, since the toner supply devices 40Y, 40M, 40C, and 40K have the same configuration, the toner supply device 40M for conveying M toner will be described.
FIG. 4 is a perspective view of the toner bottle 32M, the toner supply device 40M, and the process cartridge 6M. 5 is a front view of FIG. 4, and FIG. 6 is a bottom view of FIG. 5 and 6, illustration of the process cartridge 6M is omitted. 7A is an enlarged view of a region surrounded by a dotted line R in FIG. 4, FIG. 7B is a perspective sectional view in the AA section, and FIG. 7C is a perspective in the BB section. It is sectional drawing. The other toner replenishing devices 40Y, 40C, and 40K and the toner bottles 32Y, 32C, and 32K are also arranged in the same manner, but are not shown.

  As shown in FIGS. 5 and 6, the toner replenishing device 40M is mainly composed of a drive motor as a toner replenishment operation drive source, a hopper 48M as a toner accommodating portion, and a toner transport pipe 43M as a toner transport path. On the hopper 48M side, an agitator 80 to be described later is provided for stirring the toner in the hopper 48M. The rotating shaft 73M of the agitator 80 is provided with a stirring side bevel gear 46M. The drive from the drive motor is transmitted to the stirring side bevel gear 46M through the drive transmission gear. A toner conveyance screw 70 is inscribed inside the toner conveyance pipe 43M, and a conveyance-side bevel gear 47M is provided on the conveyance rotation shaft 71M of the toner conveyance screw 70. The conveyance side bevel gear 47M meshes with the stirring side bevel gear 46M.

  The toner conveying screw 70 of the toner replenishing device 40 shown in FIG. 8 is formed of a resin material that is flexible and can withstand sliding wear, such as an elastomer. As a result, it can be driven to rotate around the rotation shaft 73 even in a bent toner transport pipe. Instead of the toner conveying screw 70, a resin coil that can be driven and transmitted in the toner conveying pipe 43M by elastic deformation may be used.

  When the density detection sensor 56M of the developing device 5M shown in FIG. 2 detects the lack of toner density in the developer accommodating portion 54M, the drive motor is rotated by the replenishment signal from the control portion 57M. Since the spiral developer guide groove 38M is formed on the inner surface of the inner wall of the bottle main body 33M, the toner inside is conveyed from the back side of the bottle main body 33M to the resin case 34M side of the tip by rotation. As shown in FIG. 7B, the toner in the bottle main body 33M falls from the discharge port 60M of the resin case 34M into the hopper 48M of the toner replenishing device 40M.

  The hopper 48M is connected to the toner conveyance pipe 43M in the upper part. When the drive motor is rotated, the bottle main body 33M is rotated, and at the same time, the agitator 80 in the hopper 48M and the toner conveyance screw 70 in the toner conveyance pipe 43M are simultaneously rotated. . The toner that has reached the lower portion of the hopper 48M by the rotation of the toner transport screw 70M is transported in the toner transport pipe 43M, and the toner replenishing port 61M of the developer accommodating portion 54M of the developing device 5M shown in FIG. Will be replenished. In this way, the toner density in the developing device 5M is adjusted.

Here, the hopper 48, which is a characteristic part of the present embodiment, will be described in detail with reference to FIG. In the following description, the subscripts Y, M, C, and K are omitted.
FIG. 9A is a perspective view showing a schematic configuration when the inside of the hopper 48 is viewed from the upper left, and FIG. 9B is a front view of FIG. 9A.

  As shown in FIG. 9A, the hopper 48 has a first toner storage space 81 and a second toner storage space 82, and a backflow occurs between the first toner storage space 81 and the second toner storage space 82. There is a prevention wall 83. The agitator 80 is fixed to a rotation shaft 73 located substantially at the center of the first toner storage space 81. The agitator 80 is a substantially rectangular plate-like member having a thickness of about 0.05 to 0.4 mm formed of an elastic material such as a PET material.

  As shown in FIG. 9B, the uppermost end (point T in the figure) of the backflow prevention wall 83 is vertically higher than the lowest point (point M in the figure) of the inlet 84 of the toner conveying pipe 43. ing. The agitator 80 has a first bent portion 80b, a second bent portion 80d, and two bent portions from the side closer to the tip 80a, and both of the two bent portions are in the axial rotation direction (arrow V in the figure). It is bent toward the upstream side. When the tip 80a of the agitator 80 comes to the uppermost end (point T in the figure) of the agitator 80, the first bent portion 80b is higher in the vertical direction than the uppermost end of the backflow prevention wall 83. Configure to be. That is, the distance (L in the figure) from the center point of the rotating shaft 73 is greater than the vertical distance (h1 in the figure) between the center point of the rotating shaft 73 and the uppermost end (point T in the figure) of the backflow prevention wall 83. Try to be long. The agitator 80 is configured such that the tip 80 a presses the backflow prevention wall 83 when the tip 80 a passes through the backflow prevention wall 83.

  FIG. 10 is a diagram illustrating toner conveyance from the first toner storage space 81 to the second toner storage space 82 by the rotational drive of the agitator 80. FIG. 10A shows a state where the tip 80 a of the agitator 80 is pressed against the backflow prevention wall 83. FIG. 10B shows a state immediately before the tip 80a of the agitator 80 passes through the uppermost end (point T in the drawing) of the backflow prevention wall 83 and the bending is released.

  As shown in FIG. 10B, the first bent portion 80b is vertically higher than the uppermost end (point T in the drawing) of the backflow prevention wall 83, and the first bent portion 80b is in the axial rotation direction ( It is bent toward the upstream side with respect to the arrow V) in the figure. For this reason, the normal vector of the upper surface of the tip portion 80c indicated by the arrow C1 in the drawing is directed toward the second toner containing space 82. The toner at the tip 80c of the agitator 80 is scattered in the direction toward the second toner storage space 82 indicated by arrows F1, G1, H1, etc. in the figure by the restoring force when the deflection of the tip 80c is restored.

Further, among the toners at the tip 80c of the agitator 80, the toner that has not been scattered due to the restoring force is also subjected to the centrifugal force due to the rotation of the agitator 80 in the direction toward the second toner accommodating space 82 indicated by the arrow D1 in the figure. To be skipped. Since the normal vector on the upper surface of the tip portion 80c is directed toward the second toner containing space 82 (arrow C1 in the figure), the toner at the tip portion 80c of the agitator 80 is transferred to the agitator when centrifugal force is applied. The frictional force received from the upper surface of 80 in the direction of arrow I1 in the figure is small. Therefore, even if the rotational speed of the agitator 80 is the same as the conventional one, the toner at the tip 80c of the agitator 80 can be blown in the direction toward the second toner accommodating space 82 by centrifugal force.
As a result, the toner in the first toner storage space 81 can be sent to the toner conveyance path without delay.

  In order to improve the efficiency of transporting toner from the toner container to the toner transport path, the development machine described with reference to FIG. 13 rotates the agitator at a higher speed than before and transports the toner on the stirring member to the toner. It is also conceivable to increase the centrifugal force for flying toward the path. However, in this case, there is a problem of durability of sliding parts such as a bearing, a problem of toner fixing due to an increase in the temperature around the rotating shaft, and a toner between the agitator and the backflow prevention wall where the agitator is pressed. Problems such as the occurrence of aggregates occur.

In addition, if the fluidity of the toner is ensured by, for example, breaking the toner lump in the toner container, the adhesion between the toner particles in the toner pumped on the agitator can be reduced. That is, if the toner pumped onto the agitator is in a powder form rather than a lump, the toner on the agitator can be easily blown off by centrifugal force. However, if a toner breaking mechanism is installed for this purpose, there are problems such as an increase in cost due to an increase in the number of parts and an increase in installation space for the toner replenishing device.
Therefore, the present embodiment, which can improve the efficiency of transporting the toner from the toner storage portion to the toner transport path without these problems, is superior.

[Modification 1]
Next, a modified example of the agitator 80 in the present embodiment will be described.
FIGS. 11A and 11B are front views showing a schematic configuration of a hopper 48 provided with an agitator according to this modification. FIG. 11A shows a state in which the tip 80 a of the agitator 80 is pressed against the backflow prevention wall 83. The agitator 80 has only the first bent portion 80b as the bent portion. The first bent portion 80b is bent toward the upstream side with respect to the axial rotation direction (arrow V in the figure).

  FIG. 11B shows a state immediately before the tip 80a of the agitator 80 passes through the uppermost end (point T in the figure) of the backflow prevention wall 83 and the bending is released. In the agitator 80, when the tip 80a reaches the uppermost end (point T in the figure) of the backflow prevention wall 83, the first bent portion 80b is perpendicular to the uppermost end (point T in the figure) of the backflow prevention wall 83. Configure to be up in the direction. That is, the distance (L in the figure) between the tip 80a and the center point of the rotating shaft 73 is the vertical distance (h1 in the figure) between the uppermost end (point T in the figure) and the center point of the rotating shaft 73. ) To be longer.

As shown in FIG. 11A, the toner in the first toner storage space 81 is pumped up to the upper surface of the agitator 80 by the rotating agitator 80.
Further, as shown in FIG. 11 (b), the first bent portion 80b is above the uppermost end (point T in the drawing) of the backflow prevention wall 83 in the vertical direction, and the first bent portion 80b is axially rotated. It is bent toward the upstream side with respect to the direction (arrow V in the figure). For this reason, the normal vector of the upper surface of the tip portion 80c indicated by the arrow C2 in the drawing is directed toward the second toner containing space 82. The toner at the tip 80c of the agitator 80 is moved toward the second toner storage space 82 by the restoring force when the bending of the tip 80c is restored and the centrifugal force by the rotation of the agitator 80 (arrows F2, G2, in the figure). H2, D2, etc.). As a result, the toner in the first toner storage space 81 can be sent to the toner conveyance path without delay.

[Modification 2]
Next, another modification of the agitator 80 in the present embodiment will be described.
FIGS. 12A and 12B are front views showing a schematic configuration of a hopper 48 provided with an agitator according to this modification. As shown in FIG. 12 (a), the agitator 80 has a first bent portion 80b, a second bent portion 80d, and two bent portions from the side closer to the tip 80a. It is bent toward the upstream side with respect to the rotation direction (arrow V in the figure). The agitator 80 is configured so that the tip 80 a does not contact the backflow prevention wall 83 when the tip 80 a passes through the backflow prevention wall 83. When the front end 80a of the agitator 80 comes to the uppermost end (point T in the drawing) of the backflow prevention wall 83, the first bent portion 80b is positioned above the uppermost end of the backflow prevention wall 83 in the vertical direction. . That is, the distance (L in the drawing) from the rotation shaft 73 is longer than the vertical distance (h1 in the drawing) between the center point of the rotation shaft 73 and the uppermost end (point T in the drawing) of the backflow prevention wall 83. To.

  FIG. 12 (b) shows a state when the tip 80 a of the agitator 80 comes to the uppermost end (point T in the drawing) of the backflow prevention wall 83. The first bent portion 80b is above the uppermost end (point T in the figure) of the backflow prevention wall 83 in the vertical direction, and the first bent portion 80b is upstream of the axial rotation direction (arrow V in the figure). Therefore, the normal vector on the upper surface of the tip portion 80c indicated by the arrow C3 in the drawing is directed toward the second toner containing space 82. The toner at the tip 80c of the agitator 80 is scattered toward the second toner storage space 82 indicated by the arrow D3 in the figure by the centrifugal force generated by the rotation of the agitator 80. As a result, the toner in the first toner storage space 81 can be sent to the toner conveyance path without delay.

[Modification 3]
Next, still another modification of the agitator 80 in the present embodiment will be described.
FIG. 15A is a perspective view showing a schematic configuration of a hopper 48 provided with an agitator according to this modification. FIG. 15B is a perspective view of the agitator 80. As shown in FIG. 15B, the agitator 80 has a first bent portion 80b, a second bent portion 80d, and two bent portions from the side closer to the tip 80a, and both of the two bent portions are shafts. It is bent toward the upstream side with respect to the rotation direction. The tip 80c is divided into two. Further, in the present modification as well, as described with reference to FIG. 9B, when the tip 80 a of the agitator 80 comes to the uppermost end of the backflow prevention wall 83, the first bent portion 80 b has the backflow prevention wall 83. It is comprised so that it may exist above a vertical direction rather than the uppermost end.

  The aggregated toner lump is less likely to scatter even when subjected to centrifugal force by the agitator 80. If there is a lump of aggregated toner in the first toner storage space 81, toner conveyance from the first toner storage space 81 to the second toner storage space 82 is delayed. Each of the divided front end portions 80 c exerts a shearing force on the toner piles accumulated in the first toner accommodating space 81, so that the lump of toner aggregated in the first toner accommodating space 81 may be broken. it can. As a result, the toner supplied from the toner replenishment source into the first toner storage space can be sent to the toner transport path without any stagnation. Note that the number of divisions of the tip 80c is not limited to two, and may be two or more.

[Modification 4]
Next, still another modification of the agitator 80 in the present embodiment will be described.
FIG. 16A is a front view showing a schematic configuration of a hopper 48 provided with an agitator according to this modification. FIG. 16B is a perspective view of the agitator 80. In the present modification, the two tip portions 80c (first tip portion 80c_a and second tip portion 80c_b) are arranged so as to form an angle with respect to the axial direction of the rotation shaft 73 with respect to the configuration of the modification example 3 described above. Is different. That is, the direction formed by the first tip portion 80c_a indicated by the arrow I in the drawing and the direction formed by the second tip portion 80c_b indicated by the arrow J in the drawing form an angle with respect to the rotation axis direction of the rotation shaft 73. . In addition, the number of front-end | tip parts is not restricted to two, What is necessary is just two or more.

  When the agitator 80 is configured in this manner, as shown in FIG. 16A, when the first tip portion 80c_a reaches the uppermost end (point T in the figure) of the backflow prevention wall 83, the second tip portion 80c_b is still The uppermost end of the backflow prevention wall 83 is not reached. After the first tip portion 80c_a passes through the uppermost end of the backflow prevention wall 83, the second tip portion 80c_b reaches the uppermost end of the backflow prevention wall 83. Thus, the timing at which the first tip portion 80c_a and the second tip portion 80c_b reach the uppermost end of the backflow prevention wall 83 is different.

  When the first tip portion 80c_a and the second tip portion 80c_b pass through the uppermost end of the backflow prevention wall 83, the bending of the first tip portion 80c_a and the second tip portion 80c_b is released. When the deflection is released, each tip portion vibrates. This vibration is transmitted to the toner in the first toner storage space 81 through the wall of the first toner storage space 81 and the like. By causing the bending of each tip portion to be released at different timings, it is possible to increase the number of occurrences of vibration exerted on the toner. As a result, the toner can be prevented from aggregating and lumping.

  Instead of arranging the tip portions so as to form an angle with the rotation axis direction of the rotary shaft 73, the lengths of the tip portions may be different from each other. That is, as shown in FIG. 16C, the lengths of the first tip portion 80c_a and the second tip portion 80c_b are made different from each other in the configuration of the third modification described above. Even with such a configuration, the timing at which the bending of the first tip portion 80c_a and the second tip portion 80c_b is released can be made different.

[Modification 5]
Next, still another modification of the agitator 80 in the present embodiment will be described.
FIG. 17A is a front view showing a schematic configuration of a hopper 48 provided with an agitator according to this modification. FIG. 17B is a perspective view of the agitator 80. As shown in FIG. 17 (b), the agitator 80 has a first bent portion 80b, a second bent portion 80d, and two bent portions from the side closer to the tip 80a, and both of the two bent portions are shafts. It is bent toward the upstream side with respect to the rotation direction. Further, in the present modification as well, as described with reference to FIG. 9B, when the tip 80 a of the agitator 80 comes to the uppermost end of the backflow prevention wall 83, the first bent portion 80 b has the backflow prevention wall 83. It is comprised so that it may exist above a vertical direction rather than the uppermost end.

  As shown in FIG. 17A, a toner remaining amount detection sensor 84 for detecting the remaining amount of toner is generally provided on the wall surface in the first toner accommodating space 81. When the agitator 80 rotates, contact with the toner remaining amount detection sensor 84 may cause erroneous detection of the toner remaining amount detection sensor 84. In order to prevent such erroneous detection, as shown in FIG. 17B, a region that interferes with the toner remaining amount detection sensor 84 when the agitator 80 rotates is cut out. Thereby, erroneous detection of the toner remaining amount detection sensor 84 can be prevented.

[Modification 6]
Next, still another modification of the agitator 80 in the present embodiment will be described.
FIG. 18 is a front view showing a schematic configuration of a hopper 48 provided with an agitator according to this modification. As shown in FIG. 18, the agitator 80 includes a first agitator 84 and a second agitator 85. The configuration of the first agitator 84 is the same as that of the agitator 80 described in the fifth modification, and the tip is notched so as not to interfere with the toner remaining amount detection sensor 84 when rotating. On the other hand, the second agitator 85 rotates coaxially with the first agitator 84 so as to come into contact with the remaining toner amount detection sensor 84 when rotating.

  The second agitator 85 is formed of a member that is more flexible than the first agitator 84. For example, the first agitator 84 is formed of a PET material having a thickness of about 0.05 to 0.4 [mm], and the second agitator 85 is formed of a PET material that is thinner than the first agitator 84. The second agitator 85 may be formed of a member that is softer than the first agitator 84.

  Since the second agitator 85 is more easily bent than the first agitator 84, erroneous detection is unlikely to occur even when the second agitator 85 comes into contact with the toner remaining amount detection sensor 83. Further, when the second agitator 85 comes into contact with the detection surface of the toner remaining amount detection sensor during rotation, it is possible to clean the toner contamination on the detection surface of the toner remaining amount detection sensor.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A first toner storage space such as a first toner storage space 81 that is a space for storing toner supplied from a toner supply source, and a second toner storage such as a second toner storage space 82 adjacent to the first toner storage space. A toner conveying path such as a toner conveying pipe 43 that communicates with the space and the second toner accommodating space and includes a conveying member such as a toner conveying screw 70 for conveying toner into the developing device; An agitating member such as an agitator 80 for agitating the toner in the first toner accommodating space and conveying the toner in the first toner accommodating space to the second toner accommodating space by rotating in the toner accommodating space; A toner that is located between the first toner storage space and the second toner storage space and is transported from the first toner storage space to the second toner storage space. In the toner replenishing device having a backflow prevention wall such as a backflow prevention wall 83 for preventing backflow of the backflow, the stirrer member is provided with at least one bent portion that bends the stirrer member in the upstream direction with respect to the rotation direction. When the tip of the stirring member passes through the uppermost end of the backflow prevention wall, the position of the bent portion closest to the tip of the stirring member among the bent portions is perpendicular to the uppermost end of the backflow prevention wall. In the direction.
When the tip of the agitating member is at the uppermost end of the backflow prevention wall, if the bent portion closest to the tip is above the uppermost end of the backflow prevention wall in the vertical direction, it bends in the upstream direction with respect to the rotation direction. The normal vector on the upper surface of the tip end portion of the stirring member is directed toward the second toner containing space. Therefore, the toner placed on the upper surface of the stirring member portion is easily blown toward the second toner accommodating space by centrifugal force when the tip of the stirring member passes the uppermost end of the backflow prevention wall. As a result, the toner in the space for storing the toner supplied from the toner supply source into the toner storage chamber can be sent to the toner transport path without any delay.

(Aspect B)
In aspect A, the uppermost end of the backflow prevention wall is above the center point of the rotation shaft of the stirring member in the vertical direction.

(Aspect C)
In the aspect A or B, the uppermost end of the backflow prevention wall is vertically higher than the lowest point of the entrance of the toner conveyance path in the second toner containing space.

(Aspect D)
In Aspects A to C, the stirring member is formed of an elastically deformable material, and when the tip of the stirring member is in contact with the backflow prevention wall, the tip side of the stirring member is oriented upstream of the rotation direction. To bend.
Immediately before the tip of the stirring member passes through the uppermost end of the backflow prevention wall, the portion of the stirring member is bent toward the upstream side with respect to the rotation direction of the stirring member. At the moment when the tip of the stirring member passes the uppermost end of the backflow prevention wall, the deflection of the stirring member portion is released, so that the toner on the upper surface of the stirring member portion is transferred to the second toner containing space. Receives power in the direction toward. By adding this force to the centrifugal force, it is possible to further improve the efficiency of transporting the toner from the first toner storage space to the toner transport path.

(Aspect E)
The toner replenishing device according to any one of the aspects A to D, wherein a tip portion of the stirring member is divided into two or more.
Each of the tip portions divided into two or more parts applies a shearing force to the toner piles accumulated in the first toner storage space, thereby breaking up the lump of toner aggregated in the first toner storage space. Can do. As a result, the toner supplied from the toner replenishment source into the first toner storage space can be sent to the toner transport path without any stagnation.

(Aspect F)
In aspect E, the stirring member is formed such that the tip of the stirring member forms an angle with respect to the rotation axis direction.
Each tip portion of the stirring member having the tip divided into two or more vibrates when the deflection is released away from the backflow prevention wall. The vibration is transmitted to the toner in the first toner containing space through the wall portion of the first toner containing space. If two or more of the tip portions are angled with respect to the rotation axis direction of the stirring member, the timing at which the deflection of the tip portion is released away from the backflow prevention wall is different. When the bending of the tip portion is released at different timings, the number of times that the vibration is generated can be increased. This can increase the number of times the vibration is applied to the toner in the first toner storage space, thereby preventing the toner from agglomerating and lumping.

(Aspect G)
In aspect E, the stirring member was formed such that the length of the tip of the stirring member was different.
When the lengths of the two or more tip portions are different from each other, the timing at which the deflection of the tip portion is released away from the backflow prevention wall is different. Thus, the number of times the vibration is applied to the toner in the first toner storage space can be increased, so that the toner can be prevented from agglomerating and lumping.

(Aspect H)
The toner remaining amount detection sensor such as a toner remaining amount detection sensor 83 for detecting the remaining amount of toner is provided in the first toner storage space according to any one of claims A to G, and the stirring member rotates. In order to prevent the tip of the stirring member from coming into contact with the remaining toner amount detection sensor, a notch is provided in the stirring member.
By providing the notch in the stirring member, it is possible to prevent erroneous detection due to the tip of the stirring member contacting the detection surface of the toner remaining amount detection sensor.

(Aspect I)
In any one of Claims A to G, a toner remaining amount detection sensor such as a toner remaining amount detection sensor 83 for detecting the remaining amount of toner is provided in the first toner storage space, and the stirring member includes: A first agitating member such as a first agitator 84 provided with a notch so that the tip does not contact the toner remaining amount detection sensor when rotating, and the tip contacts the toner remaining amount detection sensor when rotating. The second agitator 84 and the like, and the second agitator member is formed of a member that is more flexible than the first agitator member.
If the second stirring member is formed of a member that is more flexible than the first stirring member, erroneous detection is unlikely to occur even when the second stirring member contacts the detection surface of the toner remaining amount detection sensor during rotation. Further, since the second agitating member comes into contact with the detection surface of the toner remaining amount detection sensor, it is possible to clean the detection surface due to toner.

(Aspect J)
A developing device such as a developing device 5 that develops a latent image on the latent image carrier using a latent image carrier such as the photoreceptor 1 and a developer in a developer containing portion such as the developer containing portion 54; In an image forming apparatus including a toner replenishing unit such as a toner replenishing device 40 that supplies toner to the developer accommodating portion, the toner replenishing device according to any one of aspects A to I is used as the toner replenishing unit.

(Aspect K)
In Aspect J, a small particle size polymerized toner was used as the toner in the developer used in the developing device.
According to this, it is possible to prevent the toner in the developer accommodating portion from coagulating.

(Aspect L)
In any of the aspects J or K, a premix agent in which a toner and a carrier are mixed in advance is used as the developer used in the developing device.
By using a premix agent in which toner and carrier are sufficiently mixed in advance as a developer, it is possible to prevent the toners from aggregating and forming a lump.

43 Toner conveying pipe 70 Toner conveying screw 80 Agitator 80a Tip 80b First bent portion 80c Tip portion 81 First toner containing space 82 Second toner containing space 83 Backflow prevention wall

JP 2011-215588 A

Claims (12)

A first toner storage space that is a space for storing toner supplied from a toner supply source;
A second toner containing space adjacent to the first toner containing space;
A toner transport path that communicates with the second toner storage space and includes a transport member for transporting toner into the developing device;
An agitating member that agitates the toner in the first toner accommodating space by rotating in the first toner accommodating space and conveys the toner in the first toner accommodating space to the second toner accommodating space;
A toner that is located between the first toner storage space and the second toner storage space and has a backflow prevention wall that prevents backflow of the toner conveyed from the first toner storage space to the second toner storage space. In the replenishment device,
The stirring member is provided with at least one bent portion that bends the stirring member in the upstream direction with respect to the rotation direction, and when the tip of the stirring member passes through the uppermost end of the backflow prevention wall, The toner replenishing device according to claim 1, wherein a position of the bent portion closest to the tip of the stirring member among the bent portions is located above the uppermost end of the backflow prevention wall in the vertical direction. The toner replenishing device according to claim 1.
A toner replenishing device, wherein an uppermost end of the backflow prevention wall is above a center point of a rotating shaft of the stirring member in a vertical direction. The toner replenishing device according to claim 1,
The toner replenishing device, wherein an uppermost end of the backflow prevention wall is above a lowermost point of an entrance of the toner conveyance path in the second toner containing space in a vertical direction. The toner replenishing device according to any one of claims 1 to 3,
The stirring member is formed of a material that is elastically deformed, and when the tip of the stirring member is in contact with the backflow prevention wall, the tip of the stirring member is bent toward the upstream side with respect to the rotation direction. A toner replenishing device. The toner replenishing device according to any one of claims 1 to 4,
A toner replenishing device, wherein a tip portion of the stirring member is divided into two or more. The toner replenishing device according to claim 5.
A toner replenishing device, wherein the agitation member is formed such that the tip of the agitation member is angled with respect to the rotation axis direction. The toner replenishing device according to claim 5.
The toner replenishing device, wherein the stirring member is formed such that the length of the tip of the stirring member is different. The toner replenishing device according to any one of claims 1 to 7,
The first toner storage space is provided with a toner remaining amount detection sensor for detecting the remaining amount of toner, and when the stirring member rotates, the tip of the stirring member does not contact the toner remaining amount detection sensor. In order to achieve this, a toner replenishing device, wherein the stirring member is provided with a notch. The toner replenishing device according to any one of claims 1 to 7,
The first toner storage space is provided with a toner remaining amount detection sensor for detecting the remaining amount of toner, and the stirring member is notched so that the tip does not contact the toner remaining amount detection sensor when rotating. And a second stirring member whose tip is in contact with the toner remaining amount detection sensor when rotating, and the second stirring member is more flexible than the first stirring member. A toner replenishing device formed by A latent image carrier;
A developing device for developing the latent image on the latent image carrier using the developer in the developer container;
In an image forming apparatus comprising a toner replenishing means for supplying toner to the developer containing portion,
An image forming apparatus using the toner replenishing device according to claim 1 as the toner replenishing unit. The image forming apparatus according to claim 10.
An image forming apparatus using a small particle size polymerized toner as a toner used in the developing device. The image forming apparatus according to claim 10, wherein:
An image forming apparatus, wherein a premix agent in which toner and a carrier are mixed in advance is used as a developer used in the developing device.

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